1. Field of the Invention
The present invention is generally related to a metal shield of an electrical connector and method of manufacturing, and more particular to a metal shield having continuous bent edge of an electrical connector and method of manufacturing.
2. Description of the Related Art
Port connector is a sort of necessary apparatus in transmitting signals between a computer and a peripheral apparatus. Familiar port connectors include D-shaped connectors between mainframe and a monitor of a computer, USB (Universal Serial Bus) connectors between the mainframe and a keyboard or a mouse of a computer, and IEEE 1394 (a standard established by Institute of Electrical and Electronic Engineers) connectors. In order to receive a mating plug in and provide shielding and grounding effect to ensure transmission of signals therebetween, the foregoing port connector generally has a metal exterior shield as a common characteristic. There are two known methods of manufacturing the metal shield of the electrical connector. First method is to stamping a flat rectangular piece continuously and join two edges together to produce a metal framework having a sidewall, wherein bottom edge of the framework is bent outwardly at a given angle to guide a mating plug. Most shields of conventional USB connectors made by the foregoing method are typically shown in FIG. 7. However, when the two bottoms are transfigured or shifted appreciably, rectangular shape of the shield will be damaged. In addition, bent edges 42 of metal shield 4 as shown in FIG. 7 have to be formed at bottom edges 41 but not at the corners 43 because of limitation of existing technique. The only way to revolve this is to cut the edge at the corners instead of forming bent edges, but it will affect appearance of the whole electrical connector.
Second method of manufacturing a shield is to stamping plat piece to form a rectangular framework having continuous edges from a flat carrier as shown in FIG. 8. Many connectors such as D-shaped connector, micro IEEE 1394 connector are commonly made by this approach. Referring to FIG. 8, an electrical connector having a metal shield 5 manufactured by this method is shown. It is inevitable that corners 51 of continuous edge of the shield 5 will split as shown in FIG. 8 while being bent outwardly. In addition, users are likely to be hurt by burred edges of the corners, and it will affect appearance of the electrical connector too.
Hence, an improved metal shield of electrical connector is required to overcome the disadvantages of the prior art.
Therefore, an objective of the present invention is to provide an improved metal shield of an electrical connector which has a continuous and smooth bent edge.
Another objective of the present invention is to provide a method of manufacturing a metal shield of an electrical connector to obtain a continuous and smooth bent edge to guide a mating electrical connector.
To achieve the above-mentioned objectives, in the method of the present invention, a metal shield having a continuous and smooth bent edge is produced by the following steps:
(a) stamping step: stamping a metal carrier continuously to form a framework having an underside, a continuous sidewall and a vaulted portion therebetween, the vaulted portion has a radius equal to the thickness of the carrier formed at a bottom of the sidewall, the thin edge is thinner than the sidewall;
(b) cutting step: cut the underside of the framework off that produced during the stamping step and form a thin edge at a bottom of the sidewall;
(c) trimming step: trim the thin edge of sidewall by a length equal to the radius of the vaulted portion and burrs generated while trimming the thin edge away, thereby the sidewall has equal thickness and a smooth section; and
(d) shaping step: bending the bottom of the sidewall to from at an angle of 120xcx9c170 degrees with respect to the sidewall.
According to another embodiment of the present invention, the foregoing stamping step further includes a first step to provide a suitable carrier to form the framework and a second step to stamping the carrier obtained via the first step with gradual changed punches to form a framework which has an underside and a continuous sidewall.
Metal shield manufactured by above-mentioned steps includes a continuous sidewall and a bugle-like portion, wherein the sidewall covers an insulative housing of the electrical connector and the bugle-shaped edge is to guide a mating electrical connector.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings.